waitpid 收集子進程的的信息

       $ ./a.out &        Child PID is 32360        [1] 32359        $ kill -STOP 32360        stopped by signal 19        $ kill -CONT 32360        continued        $ kill -TERM 32360        killed by signal 15        [1]+  Done                    ./a.out        $        #include <sys/wait.h>        #include <stdlib.h>        #include <unistd.h>        #include <stdio.h>        int        main(int argc, char *argv[])        {            pid_t cpid, w;            int status;            cpid = fork();            if (cpid == -1) { perror("fork"); exit(EXIT_FAILURE); }            if (cpid == 0) {            /* Code executed by child */                printf("Child PID is %ld\n", (long) getpid());                if (argc == 1)                    pause();                    /* Wait for signals */                _exit(atoi(argv[1])); } else {                    /* Code executed by parent */                do {                    w = waitpid(cpid, &status, WUNTRACED | WCONTINUED);                    if (w == -1) { perror("waitpid"); exit(EXIT_FAILURE); }                    if (WIFEXITED(status)) {                        printf("exited, status=%d\n", WEXITSTATUS(status));                    } else if (WIFSIGNALED(status)) {                        printf("killed by signal %d\n", WTERMSIG(status));                    } else if (WIFSTOPPED(status)) {                        printf("stopped by signal %d\n", WSTOPSIG(status));                    } else if (WIFCONTINUED(status)) {                        printf("continued\n");                    }                } while (!WIFEXITED(status) && !WIFSIGNALED(status));                exit(EXIT_SUCCESS);            }        }